Solutions of dihydrocarbylmagnesium compounds are known to develop haziness over time. In dihydrocarbylmagnesium solutions, which are often viscous, the solids causing the haze settle very slowly. Haze formation has been ascribed to precipitation of dissolved chloride salts; thus, efforts have been made to remove these chloride salts from the dihydrocarbylmagnesium solutions. U.S. Pat. No. 4,615,843 discloses the use of alkyllithium compounds to reduce soluble chlorides. However, it was noted therein that care must be taken in order to minimize the amount of lithium in the solution, especially when a viscosity reducing agent is present in the solution with the dihydrocarbyl-magnesium compound, because the lithium from the alkyllithium compound may remain with the dihydrocarbylmagnesium compound.
The addition of alkali metals to dihydrocarbylmagnesium compounds in both solutions and slurries has been reported in the literature by Malpass and Eastham, J. Org. Chem., 1973, 38, 3718-3723. The alkali metals were added to the dihydrocarbyl-magnesium compounds at a mole ratio of alkali metal to magnesium of about 1:1, with the alkali metal usually in excess relative to magnesium. The findings were that the stoichiometry of the reaction of the alkali metal with the dihydrocarbylmagnesium compound varied with the alkali metal used. Products having alkali metal, magnesium, and alkyl groups in varying proportions were formed. In many instances, precipitation of magnesium metal was observed.